Video jack on vintage TV?

[CaryLee]

I never really thought about it before..

I understand a PHONO jack on a vintage TV. Just like a vintage radio, one can hook up an electric phonograph and play sound through the TV's amp and speaker.

Perhaps the answer is so simple I'm going to kick my own butt when someone mentions it, but my vintage (1950) TV has a VIDEO jack right next to the PHONO jack.

What did they have, in 1950, that would require a VIDEO jack on a television?

[old_tv_nut]

Is it video in or out? If it's video out, it could be intended for a color adaptor, I guess. What brand is it? Could it be intended as a closed-circuit monitor?

[bandersen]

Is this your Dumont TV ? If so, I think you're referring to the RF antenna jack. You can get a male RCA to female F-connector and hook it up to an 75 ohm RF source like an OTA digital receiver, analog cable, VCR, RF modulator etc.

[CaryLee]

It is the DuMont set. Here's a photo. Notice on lower left the jack marked "ANT" on the chassis. And then upper right there's an aluminum plate with two more jacks, one marked PHONO and one marked VIDEO.

There's no "VIDEO" setting on any of the dials up front...so I'm kind of puzzled by it.

[bandersen]

OK, the RA113 I worked on didn't have that. I dug up this discussion thread from a few years ago that says it is for a color adaptor as 'old tv nut' suggested.
http://www.videokarma.org/showthread.php?t=252360

[Kamakiri]

Soon as I saw that, I had to swing mine around for a peek. Mine doesn't have it either....

[earlyfilm]

Originally Posted by CaryLee

What did they have, in 1950, that would require a VIDEO jack on a television?

As Electronic M mentioned in the other thread, his Majestic has the color output and so does my Majestic 712, which carries a common late 1950-1952 Majestic chassis.

The Sam's is here:

http://www.earlytelevision.org/tv_sc...s_postwar.html

Majestic apparently just relabeled and rewired the phono input switch on the back to be the "color" switch. However, they left the phono input in place and added a new phono switch in the pencil box as they assumed more people would be using that function than color. They would not want their kids reaching around to the back of the set to use their new RCA 45 RPM turntables that they kept on top of the TV.

I've not restored the set yet, but the color switch disconnects the cathode and G1 of the CRT and switches the video output via a .2 MFD capacitor to a three pin socket on the back. The phono switch apparently leaves the CRT running but blacks it out by causing the CRT cathode to go more positive.

Back before I switched careers and was doing TV repair (1957-1960), I remember two older sets coming in the shop that had these "color" adapters. At the time I was thinking NTSC color and assumed these were frauds. On one set the color socket was not electrically connected and the other went via capacitor to the video signal and did not have a switch. I cannot remember the brands, but the never-wired one was a copper color chassis.

Attached is the paste-on label on the back of my set.

Oops! My attachment just went bye-bye.

[Einar72]

My first KCS-47 has a phono jack in the video path, unfortunately it's in storage and my 1950-51 RCA Service Directory is hiding, or I'd have a photo. The SAMS folder doesn't show it. However, the 1952 Service Directory shows several KCS-66/68/72 chassis with a jack in the video amplifier cathode circuit...

[kramden66]

they had vcrs and dvds back then ?

[Einar72]

In 1950, the principal means of recording television programming was transcription from a live CRT to a film camera. Dumont's Electronicam is good example, which is mentioned in the ending credits of first-gen Honeymooners episodes. There are folks on VK who can explain the history of video tape technology, which didn't arrive until about 1956 and were the size of a refrigerator, but home-recording systems didn't really arrive until the mid-1960's,and boy, were they expensive!

http://www.youtube.com/watch?v=lTefbj4I8hs

[jr_tech]

As I understand it, the Electronicam was an improvement over transcription from CRT to film camera (Kinescope Recordings) in that it involved a dual camera/beam splitter to provide video as well as a film record.

http://en.wikipedia.org/wiki/Electronicam

jr

[Dave A]

A kinescope of Honeymooners would also be recorded for delay and that was used as a guide for editing the 35mm Electronicam print later.